Following my previous post “lift-gamma-gain color correction formula with blender compositing” I continue my research about all those formulas.
Comparison
I came to compare the ASC CDL (American Society of Cinematographers Color Decision List) formula to the Lift/Gamma/Gain formula I found on Blender.org
Here are the results :
Where the formula are :
- CDL : ((input*slope)+offset)^(1/gamma)
- Lift : gain * (input + lift * (1 – input)^(1/gamma))
(slope = gain ; offset = lift)
You can see that CDL is able to burn (exposure) the white, while the Lift will keep the white unchanged as much as it can.
_dbr did a nice test for me in Shake and create a graph that really shows the differences
so in both formula by only changing Lift/Offset, you can see clearly that the lift keep the white unchanged while CDL push the black and white as well.
HLSL Shader in Media Player Classic
Yes, in Media Player Classic, you can write shaders compiled in runtime while you are watching your favourite TV Shows ^^ . Awesome !!!
Conclusion
So I guess CDL is much easier to use, but I believe that Lift could give you much control other the image. What would need Lift to be able to push the white as well would be an exposure parameter! (which is the goal of my next shader 
)
[...] described the Lift/Gamma/Gain in a previous post, and mostly this node is based on the formulas specified there. We just slightly modified it so the [...]